Shewanella is a genus of Gram-negative, curved or straight rods of the family Alteromonadaceae, able to grow with or without oxygen. Shewanella putrefaciens spoils of fish and meat, producing putrid off-odours even under refrigeration. Its presence and activity are classic indicators of cold-chain failure, making it a useful organism for shelf-life studies. Keeping fish well chilled suppresses its growth. Temperature control is the best defence. It is a sentinel of seafood freshness. Keep seafood cold and safe. Cold chain discipline controls it.